Chroma/chroma/system/memory/liballoc.c

877 lines
20 KiB
C

#include <stdint.h>
#include <kernel/system/memory.h>
/** Durand's Amazing Super Duper Memory functions. */
#define VERSION "1.1"
#define ALIGNMENT 16ul//4ul ///< This is the byte alignment that memory must be allocated on. IMPORTANT for GTK and other stuff.
#define ALIGN_TYPE char ///unsigned char[16] /// unsigned short
#define ALIGN_INFO sizeof(ALIGN_TYPE)*16 ///< Alignment information is stored right before the pointer. This is the number of bytes of information stored there.
#define USE_CASE1
#define USE_CASE2
#define USE_CASE3
#define USE_CASE4
#define USE_CASE5
extern address_space_t KernelAddressSpace;
/** This function is supposed to lock the memory data structures. It
* could be as simple as disabling interrupts or acquiring a spinlock.
* It's up to you to decide.
*
* \return 0 if the lock was acquired successfully. Anything else is
* failure.
*/
static int liballoc_lock() {
return TicketAttemptLock(&KernelAddressSpace.Lock) ? 0 : 1;
}
/** This function unlocks what was previously locked by the liballoc_lock
* function. If it disabled interrupts, it enables interrupts. If it
* had acquiried a spinlock, it releases the spinlock. etc.
*
*/
static void liballoc_unlock() {
TicketUnlock(&KernelAddressSpace.Lock);
}
/** This is the hook into the local system which allocates pages. It
* accepts an integer parameter which is the number of pages
* required. The page size was set up in the liballoc_init function.
*
* \return NULL if the pages were not allocated.
* \return A pointer to the allocated memory.
*/
static void* liballoc_alloc(size_t count) {
return (void*) PhysAllocateMem(count * PAGE_SIZE);
}
/** This frees previously allocated memory. The void* parameter passed
* to the function is the exact same value returned from a previous
* liballoc_alloc call.
*
* The integer value is the number of pages to free.
*
* \return 0 if the memory was successfully freed.
*/
static int liballoc_free(void* ptr, size_t count) {
PhysFreeMem(ptr, count * PAGE_SIZE);
return 0;
}
/** This macro will conveniently align our pointer upwards */
#define ALIGN( ptr ) \
if ( ALIGNMENT > 1 ) \
{ \
uintptr_t diff; \
ptr = (void*)((uintptr_t)ptr + ALIGN_INFO); \
diff = (uintptr_t)ptr & (ALIGNMENT-1); \
if ( diff != 0 ) \
{ \
diff = ALIGNMENT - diff; \
ptr = (void*)((uintptr_t)ptr + diff); \
} \
*((ALIGN_TYPE*)((uintptr_t)ptr - ALIGN_INFO)) = \
diff + ALIGN_INFO; \
}
#define UNALIGN( ptr ) \
if ( ALIGNMENT > 1 ) \
{ \
uintptr_t diff = *((ALIGN_TYPE*)((uintptr_t)ptr - ALIGN_INFO)); \
if ( diff < (ALIGNMENT + ALIGN_INFO) ) \
{ \
ptr = (void*)((uintptr_t)ptr - diff); \
} \
}
#define LIBALLOC_MAGIC 0xc001c0de
#define LIBALLOC_DEAD 0xdeaddead
#if defined DEBUG || defined INFO
#include <stdio.h>
#include <stdlib.h>
#define FLUSH() fflush( stdout )
#endif
/** A structure found at the top of all system allocated
* memory blocks. It details the usage of the memory block.
*/
struct liballoc_major
{
struct liballoc_major *prev; ///< Linked list information.
struct liballoc_major *next; ///< Linked list information.
unsigned int pages; ///< The number of pages in the block.
unsigned int size; ///< The number of pages in the block.
unsigned int usage; ///< The number of bytes used in the block.
struct liballoc_minor *first; ///< A pointer to the first allocated memory in the block.
};
/** This is a structure found at the beginning of all
* sections in a major block which were allocated by a
* malloc, calloc, realloc call.
*/
struct liballoc_minor
{
struct liballoc_minor *prev; ///< Linked list information.
struct liballoc_minor *next; ///< Linked list information.
struct liballoc_major *block; ///< The owning block. A pointer to the major structure.
unsigned int magic; ///< A magic number to idenfity correctness.
unsigned int size; ///< The size of the memory allocated. Could be 1 byte or more.
unsigned int req_size; ///< The size of memory requested.
};
static struct liballoc_major *l_memRoot = NULL; ///< The root memory block acquired from the system.
static struct liballoc_major *l_bestBet = NULL; ///< The major with the most free memory.
static unsigned int l_pageSize = 4096; ///< The size of an individual page. Set up in liballoc_init.
static unsigned int l_pageCount = 16; ///< The number of pages to request per chunk. Set up in liballoc_init.
static unsigned long long l_allocated = 0; ///< Running total of allocated memory.
static unsigned long long l_inuse = 0; ///< Running total of used memory.
static long long l_warningCount = 0; ///< Number of warnings encountered
static long long l_errorCount = 0; ///< Number of actual errors
static long long l_possibleOverruns = 0; ///< Number of possible overruns
// *********** HELPER FUNCTIONS *******************************
static void *liballoc_memset(void* s, int c, size_t n)
{
unsigned int i;
for ( i = 0; i < n ; i++)
((char*)s)[i] = c;
return s;
}
static void* liballoc_memcpy(void* s1, const void* s2, size_t n)
{
char *cdest;
char *csrc;
unsigned int *ldest = (unsigned int*)s1;
unsigned int *lsrc = (unsigned int*)s2;
while ( n >= sizeof(unsigned int) )
{
*ldest++ = *lsrc++;
n -= sizeof(unsigned int);
}
cdest = (char*)ldest;
csrc = (char*)lsrc;
while ( n > 0 )
{
*cdest++ = *csrc++;
n -= 1;
}
return s1;
}
#if defined DEBUG || defined INFO
static void liballoc_dump()
{
#ifdef DEBUG
struct liballoc_major *maj = l_memRoot;
struct liballoc_minor *min = NULL;
#endif
printf( "liballoc: ------ Memory data ---------------\n");
printf( "liballoc: System memory allocated: %i bytes\n", l_allocated );
printf( "liballoc: Memory in used (malloc'ed): %i bytes\n", l_inuse );
printf( "liballoc: Warning count: %i\n", l_warningCount );
printf( "liballoc: Error count: %i\n", l_errorCount );
printf( "liballoc: Possible overruns: %i\n", l_possibleOverruns );
#ifdef DEBUG
while ( maj != NULL )
{
printf( "liballoc: %x: total = %i, used = %i\n",
maj,
maj->size,
maj->usage );
min = maj->first;
while ( min != NULL )
{
printf( "liballoc: %x: %i bytes\n",
min,
min->size );
min = min->next;
}
maj = maj->next;
}
#endif
FLUSH();
}
#endif
// ***************************************************************
static struct liballoc_major *allocate_new_page( unsigned int size )
{
unsigned int st;
struct liballoc_major *maj;
// This is how much space is required.
st = size + sizeof(struct liballoc_major);
st += sizeof(struct liballoc_minor);
// Perfect amount of space?
if ( (st % l_pageSize) == 0 )
st = st / (l_pageSize);
else
st = st / (l_pageSize) + 1;
// No, add the buffer.
// Make sure it's >= the minimum size.
if ( st < l_pageCount ) st = l_pageCount;
maj = (struct liballoc_major*)liballoc_alloc( st );
if ( maj == NULL )
{
l_warningCount += 1;
#if defined DEBUG || defined INFO
printf( "liballoc: WARNING: liballoc_alloc( %i ) return NULL\n", st );
FLUSH();
#endif
return NULL; // uh oh, we ran out of memory.
}
maj->prev = NULL;
maj->next = NULL;
maj->pages = st;
maj->size = st * l_pageSize;
maj->usage = sizeof(struct liballoc_major);
maj->first = NULL;
l_allocated += maj->size;
#ifdef DEBUG
printf( "liballoc: Resource allocated %x of %i pages (%i bytes) for %i size.\n", maj, st, maj->size, size );
printf( "liballoc: Total memory usage = %i KB\n", (int)((l_allocated / (1024))) );
FLUSH();
#endif
return maj;
}
void *PREFIX(malloc)(size_t req_size)
{
int startedBet = 0;
unsigned long long bestSize = 0;
void *p = NULL;
uintptr_t diff;
struct liballoc_major *maj;
struct liballoc_minor *min;
struct liballoc_minor *new_min;
unsigned long size = req_size;
// For alignment, we adjust size so there's enough space to align.
if ( ALIGNMENT > 1 )
{
size += ALIGNMENT + ALIGN_INFO;
}
// So, ideally, we really want an alignment of 0 or 1 in order
// to save space.
liballoc_lock();
if ( size == 0 )
{
l_warningCount += 1;
#if defined DEBUG || defined INFO
printf( "liballoc: WARNING: alloc( 0 ) called from %x\n",
__builtin_return_address(0) );
FLUSH();
#endif
liballoc_unlock();
return PREFIX(malloc)(1);
}
if ( l_memRoot == NULL )
{
#if defined DEBUG || defined INFO
#ifdef DEBUG
printf( "liballoc: initialization of liballoc " VERSION "\n" );
#endif
atexit( liballoc_dump );
FLUSH();
#endif
// This is the first time we are being used.
l_memRoot = allocate_new_page( size );
if ( l_memRoot == NULL )
{
liballoc_unlock();
#ifdef DEBUG
printf( "liballoc: initial l_memRoot initialization failed\n", p);
FLUSH();
#endif
return NULL;
}
#ifdef DEBUG
printf( "liballoc: set up first memory major %x\n", l_memRoot );
FLUSH();
#endif
}
#ifdef DEBUG
printf( "liballoc: %x PREFIX(malloc)( %i ): ",
__builtin_return_address(0),
size );
FLUSH();
#endif
// Now we need to bounce through every major and find enough space....
maj = l_memRoot;
startedBet = 0;
// Start at the best bet....
if ( l_bestBet != NULL )
{
bestSize = l_bestBet->size - l_bestBet->usage;
if ( bestSize > (size + sizeof(struct liballoc_minor)))
{
maj = l_bestBet;
startedBet = 1;
}
}
while ( maj != NULL )
{
diff = maj->size - maj->usage;
// free memory in the block
if ( bestSize < diff )
{
// Hmm.. this one has more memory then our bestBet. Remember!
l_bestBet = maj;
bestSize = diff;
}
#ifdef USE_CASE1
// CASE 1: There is not enough space in this major block.
if ( diff < (size + sizeof( struct liballoc_minor )) )
{
#ifdef DEBUG
printf( "CASE 1: Insufficient space in block %x\n", maj);
FLUSH();
#endif
// Another major block next to this one?
if ( maj->next != NULL )
{
maj = maj->next; // Hop to that one.
continue;
}
if ( startedBet == 1 ) // If we started at the best bet,
{ // let's start all over again.
maj = l_memRoot;
startedBet = 0;
continue;
}
// Create a new major block next to this one and...
maj->next = allocate_new_page( size ); // next one will be okay.
if ( maj->next == NULL ) break; // no more memory.
maj->next->prev = maj;
maj = maj->next;
// .. fall through to CASE 2 ..
}
#endif
#ifdef USE_CASE2
// CASE 2: It's a brand new block.
if ( maj->first == NULL )
{
maj->first = (struct liballoc_minor*)((uintptr_t)maj + sizeof(struct liballoc_major) );
maj->first->magic = LIBALLOC_MAGIC;
maj->first->prev = NULL;
maj->first->next = NULL;
maj->first->block = maj;
maj->first->size = size;
maj->first->req_size = req_size;
maj->usage += size + sizeof( struct liballoc_minor );
l_inuse += size;
p = (void*)((uintptr_t)(maj->first) + sizeof( struct liballoc_minor ));
ALIGN( p );
#ifdef DEBUG
printf( "CASE 2: returning %x\n", p);
FLUSH();
#endif
liballoc_unlock(); // release the lock
return p;
}
#endif
#ifdef USE_CASE3
// CASE 3: Block in use and enough space at the start of the block.
diff = (uintptr_t)(maj->first);
diff -= (uintptr_t)maj;
diff -= sizeof(struct liballoc_major);
if ( diff >= (size + sizeof(struct liballoc_minor)) )
{
// Yes, space in front. Squeeze in.
maj->first->prev = (struct liballoc_minor*)((uintptr_t)maj + sizeof(struct liballoc_major) );
maj->first->prev->next = maj->first;
maj->first = maj->first->prev;
maj->first->magic = LIBALLOC_MAGIC;
maj->first->prev = NULL;
maj->first->block = maj;
maj->first->size = size;
maj->first->req_size = req_size;
maj->usage += size + sizeof( struct liballoc_minor );
l_inuse += size;
p = (void*)((uintptr_t)(maj->first) + sizeof( struct liballoc_minor ));
ALIGN( p );
#ifdef DEBUG
printf( "CASE 3: returning %x\n", p);
FLUSH();
#endif
liballoc_unlock(); // release the lock
return p;
}
#endif
#ifdef USE_CASE4
// CASE 4: There is enough space in this block. But is it contiguous?
min = maj->first;
// Looping within the block now...
while ( min != NULL )
{
// CASE 4.1: End of minors in a block. Space from last and end?
if ( min->next == NULL )
{
// the rest of this block is free... is it big enough?
diff = (uintptr_t)(maj) + maj->size;
diff -= (uintptr_t)min;
diff -= sizeof( struct liballoc_minor );
diff -= min->size;
// minus already existing usage..
if ( diff >= (size + sizeof( struct liballoc_minor )) )
{
// yay....
min->next = (struct liballoc_minor*)((uintptr_t)min + sizeof( struct liballoc_minor ) + min->size);
min->next->prev = min;
min = min->next;
min->next = NULL;
min->magic = LIBALLOC_MAGIC;
min->block = maj;
min->size = size;
min->req_size = req_size;
maj->usage += size + sizeof( struct liballoc_minor );
l_inuse += size;
p = (void*)((uintptr_t)min + sizeof( struct liballoc_minor ));
ALIGN( p );
#ifdef DEBUG
printf( "CASE 4.1: returning %x\n", p);
FLUSH();
#endif
liballoc_unlock(); // release the lock
return p;
}
}
// CASE 4.2: Is there space between two minors?
if ( min->next != NULL )
{
// is the difference between here and next big enough?
diff = (uintptr_t)(min->next);
diff -= (uintptr_t)min;
diff -= sizeof( struct liballoc_minor );
diff -= min->size;
// minus our existing usage.
if ( diff >= (size + sizeof( struct liballoc_minor )) )
{
// yay......
new_min = (struct liballoc_minor*)((uintptr_t)min + sizeof( struct liballoc_minor ) + min->size);
new_min->magic = LIBALLOC_MAGIC;
new_min->next = min->next;
new_min->prev = min;
new_min->size = size;
new_min->req_size = req_size;
new_min->block = maj;
min->next->prev = new_min;
min->next = new_min;
maj->usage += size + sizeof( struct liballoc_minor );
l_inuse += size;
p = (void*)((uintptr_t)new_min + sizeof( struct liballoc_minor ));
ALIGN( p );
#ifdef DEBUG
printf( "CASE 4.2: returning %x\n", p);
FLUSH();
#endif
liballoc_unlock(); // release the lock
return p;
}
} // min->next != NULL
min = min->next;
} // while min != NULL ...
#endif
#ifdef USE_CASE5
// CASE 5: Block full! Ensure next block and loop.
if ( maj->next == NULL )
{
#ifdef DEBUG
printf( "CASE 5: block full\n");
FLUSH();
#endif
if ( startedBet == 1 )
{
maj = l_memRoot;
startedBet = 0;
continue;
}
// we've run out. we need more...
maj->next = allocate_new_page( size ); // next one guaranteed to be okay
if ( maj->next == NULL ) break; // uh oh, no more memory.....
maj->next->prev = maj;
}
#endif
maj = maj->next;
} // while (maj != NULL)
liballoc_unlock(); // release the lock
#ifdef DEBUG
printf( "All cases exhausted. No memory available.\n");
FLUSH();
#endif
#if defined DEBUG || defined INFO
printf( "liballoc: WARNING: PREFIX(malloc)( %i ) returning NULL.\n", size);
liballoc_dump();
FLUSH();
#endif
return NULL;
}
void PREFIX(free)(void *ptr)
{
struct liballoc_minor *min;
struct liballoc_major *maj;
if ( ptr == NULL )
{
l_warningCount += 1;
#if defined DEBUG || defined INFO
printf( "liballoc: WARNING: PREFIX(free)( NULL ) called from %x\n",
__builtin_return_address(0) );
FLUSH();
#endif
return;
}
UNALIGN( ptr );
liballoc_lock(); // lockit
min = (struct liballoc_minor*)((uintptr_t)ptr - sizeof( struct liballoc_minor ));
if ( min->magic != LIBALLOC_MAGIC )
{
l_errorCount += 1;
// Check for overrun errors. For all bytes of LIBALLOC_MAGIC
if (
((min->magic & 0xFFFFFF) == (LIBALLOC_MAGIC & 0xFFFFFF)) ||
((min->magic & 0xFFFF) == (LIBALLOC_MAGIC & 0xFFFF)) ||
((min->magic & 0xFF) == (LIBALLOC_MAGIC & 0xFF))
)
{
l_possibleOverruns += 1;
#if defined DEBUG || defined INFO
printf( "liballoc: ERROR: Possible 1-3 byte overrun for magic %x != %x\n",
min->magic,
LIBALLOC_MAGIC );
FLUSH();
#endif
}
if ( min->magic == LIBALLOC_DEAD )
{
#if defined DEBUG || defined INFO
printf( "liballoc: ERROR: multiple PREFIX(free)() attempt on %x from %x.\n",
ptr,
__builtin_return_address(0) );
FLUSH();
#endif
}
else
{
#if defined DEBUG || defined INFO
printf( "liballoc: ERROR: Bad PREFIX(free)( %x ) called from %x\n",
ptr,
__builtin_return_address(0) );
FLUSH();
#endif
}
// being lied to...
liballoc_unlock(); // release the lock
return;
}
#ifdef DEBUG
printf( "liballoc: %x PREFIX(free)( %x ): ",
__builtin_return_address( 0 ),
ptr );
FLUSH();
#endif
maj = min->block;
l_inuse -= min->size;
maj->usage -= (min->size + sizeof( struct liballoc_minor ));
min->magic = LIBALLOC_DEAD; // No mojo.
if ( min->next != NULL ) min->next->prev = min->prev;
if ( min->prev != NULL ) min->prev->next = min->next;
if ( min->prev == NULL ) maj->first = min->next;
// Might empty the block. This was the first
// minor.
// We need to clean up after the majors now....
if ( maj->first == NULL ) // Block completely unused.
{
if ( l_memRoot == maj ) l_memRoot = maj->next;
if ( l_bestBet == maj ) l_bestBet = NULL;
if ( maj->prev != NULL ) maj->prev->next = maj->next;
if ( maj->next != NULL ) maj->next->prev = maj->prev;
l_allocated -= maj->size;
liballoc_free( maj, maj->pages );
}
else
{
if ( l_bestBet != NULL )
{
int bestSize = l_bestBet->size - l_bestBet->usage;
int majSize = maj->size - maj->usage;
if ( majSize > bestSize ) l_bestBet = maj;
}
}
#ifdef DEBUG
printf( "OK\n");
FLUSH();
#endif
liballoc_unlock(); // release the lock
}
void* PREFIX(calloc)(size_t nobj, size_t size)
{
int real_size;
void *p;
real_size = nobj * size;
p = PREFIX(malloc)( real_size );
liballoc_memset( p, 0, real_size );
return p;
}
void* PREFIX(realloc)(void *p, size_t size)
{
void *ptr;
struct liballoc_minor *min;
unsigned int real_size;
// Honour the case of size == 0 => free old and return NULL
if ( size == 0 )
{
PREFIX(free)( p );
return NULL;
}
// In the case of a NULL pointer, return a simple malloc.
if ( p == NULL ) return PREFIX(malloc)( size );
// Unalign the pointer if required.
ptr = p;
UNALIGN(ptr);
liballoc_lock(); // lockit
min = (struct liballoc_minor*)((uintptr_t)ptr - sizeof( struct liballoc_minor ));
// Ensure it is a valid structure.
if ( min->magic != LIBALLOC_MAGIC )
{
l_errorCount += 1;
// Check for overrun errors. For all bytes of LIBALLOC_MAGIC
if (
((min->magic & 0xFFFFFF) == (LIBALLOC_MAGIC & 0xFFFFFF)) ||
((min->magic & 0xFFFF) == (LIBALLOC_MAGIC & 0xFFFF)) ||
((min->magic & 0xFF) == (LIBALLOC_MAGIC & 0xFF))
)
{
l_possibleOverruns += 1;
#if defined DEBUG || defined INFO
printf( "liballoc: ERROR: Possible 1-3 byte overrun for magic %x != %x\n",
min->magic,
LIBALLOC_MAGIC );
FLUSH();
#endif
}
if ( min->magic == LIBALLOC_DEAD )
{
#if defined DEBUG || defined INFO
printf( "liballoc: ERROR: multiple PREFIX(free)() attempt on %x from %x.\n",
ptr,
__builtin_return_address(0) );
FLUSH();
#endif
}
else
{
#if defined DEBUG || defined INFO
printf( "liballoc: ERROR: Bad PREFIX(free)( %x ) called from %x\n",
ptr,
__builtin_return_address(0) );
FLUSH();
#endif
}
// being lied to...
liballoc_unlock(); // release the lock
return NULL;
}
// Definitely a memory block.
real_size = min->req_size;
if ( real_size >= size )
{
min->req_size = size;
liballoc_unlock();
return p;
}
liballoc_unlock();
// If we got here then we're reallocating to a block bigger than us.
ptr = PREFIX(malloc)( size ); // We need to allocate new memory
liballoc_memcpy( ptr, p, real_size );
PREFIX(free)( p );
return ptr;
}